Why All Fat Is Not Created EqualEating a diet high in fat isn't good for us. But demonizing fat didn't lead us down a healthy path either. Some fats, especially plant-based fats such olive oil are good for us.

Eating a diet high in fat isn't good for us. But demonizing fat didn't lead us down a healthy path either. Some fats, especially plant-based fats such olive oil are good for us.

DAVID GREENE, HOST:

All right, that story on that came to us from NPR's Allison Aubrey who joins us in the studio now. And, Allison, Elizabeth, right there at the end sounded very relieved to be eating fat again, a burger.

ALLISON AUBREY, BYLINE: That's right. She did.

GREENE: And, yeah, and I'm wondering does this mean that we can bring back the burgers? Bring back the bacon? Would make me very happy.

AUBREY: Ah-ha. That's what you're looking for here. Yeah.

(LAUGHTER)

AUBREY: Well, you know, I don't know of any health experts who would say; bring back burgers and bacon to every meal.

GREENE: OK.

And I think the lesson here is what happens when the pendulum just swings too far in one direction, right? Demonizing fat led us down a path of eating too many carbs.

AUBREY: So, let's put this into perspective. If you want to try to answer the question is fat and bad for us...

GREENE: Mm-hmm.

AUBREY: ...you've kind of got to ask two questions: What kind of fat and compared to what? I mean we just heard the case in this piece that compared to carbs - especially refined starches, so bagels, you know, white pasta, fats are not so bad.

The thinking of the experts I spoke to is that in the case of most animal fats, they have kind of a neutral effect. They don't seem to increase the risk of heart disease and they don't seem to reduce the risk either. And it's turned out that some fats, especially plant-based fats, such as olive oil, are actually good for us.

GREENE: This is why we're hearing more and more encouragement that, you know, the more olive oil, the better - even if it has a lot of fat.

AUBREY: That's right. That's right. I mean if you replace a diet high in refined carbohydrates and sugar - this is what the research is showing - with a lot of plant-based fats, such as olive oil and nuts, then, yes. I mean experts such as Walter Willett say there is clear evidence that these plant-based fats lower the risk of heart disease. And it's also clear that eating fatty fish has a similar beneficial effect on our heart.

GREENE: OK. Olive oil, potentially good for us; fatty fish, beneficial. What about other kinds of animals fat now?

AUBREY: You know, this is where the thinking is kind of changing. The experts I spoke to pointed dairy. There's growing evidence that there's something about full fat milk or yogurt with a little fat in it that could be protective against heart disease.

Now it could be the kind of fatty acids that make up the dairy fat, or it could be something else entirely, some other compounds in milk. Scientists don't know. But it's an active area of research. And I think the lesson here is that you can't just judge the healthfulness of a food simply by reducing it down to its fat content.

GREENE: So what you're talking about here and what we heard in your piece, are experts pretty much on board with this?

AUBREY: Well, no. There's a lot of controversy here. All of these studies that question the link between saturated fat and heart disease have led to a lot of questions. And understandably, you know, this is challenging what had become almost gospel. The fear of fat runs really deep. And, the American Heart Association says it does stand by its advice to limit saturated fat.

But here's the common ground. All of the experts I spoke to, including those who challenge the old assumptions about fat, and groups like the American Heart Association, they tell me that they mostly agree on what a healthy pattern of eating looks like.

A healthy diet is one that adds in, you know, a huge variety of fruits, vegetables, legumes - so peas and beans and whole grains, nuts. And this is basically the Mediterranean approach, right? We've heard of that.

Walter Willett told me that if you look at studies of the Mediterranean diet - which is linked to longevity and good health - there's a little bit of everything, including yogurt, cheese and small portions of meat. So that doesn't sound like a fat-free diet, does it?

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